Gynandromorphism
Gynandromorphism is the phenomenon that occurs when an individual organism possesses both male and female phenotypes due to genetic chimera of sex chromosomes in cells across the body and is most easily recognized in species that display sexual dimorphism<ref name=":0">Template:Cite journal</ref>. An individual who displays this characteristic is called a gynandromorph. The term comes from the Greek γυνή (gynē) 'female', ἀνήρ (anēr) 'male', and μορφή (morphē) 'form', and is most commonly documented the field of entomology.<ref name=":0" /> The definition of “gynandromorphism” is distinct from both intersexuality and hermaphroditism, although they are sometimes used interchangeably.<ref name=":1">Template:Cite journal</ref>
OccurrenceEdit
Gynandromorphism has been noted in Lepidoptera (butterflies and moths) since the 1700s.<ref name="Rudolphi">Template:Cite journal</ref><ref name="Packard1875">Template:Cite journal</ref><ref name="Pavid">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It has also been observed in crustaceans, such as lobsters and crabs, in spiders,<ref>Template:Cite journal</ref> ticks,<ref name="Labruna">Template:Cite journal</ref> flies,<ref name="Morgan1914">Template:Cite journal</ref> locusts,<ref name="Maeno">Template:Cite journal</ref> crickets,<ref name="Taniyama">Template:Cite journal</ref> dragonflies,<ref name="Renjith2020">Template:Cite journal</ref> ants,<ref name="Donisthorpe">Template:Cite journal</ref><ref name="Cokendolpher">Template:Cite journal</ref> termites,<ref name="Miyaguni2017">Template:Cite journal</ref> bees,<ref name="Lucia2013">Template:Cite journal</ref> lizards,<ref name="Mitchell1978">Template:Cite journal</ref> snakes,<ref name="Krohmer1989">Template:Cite journal</ref> rodents,<ref name="Asdell1942">Template:Cite journal</ref><ref name="Hollander1956">Template:Cite journal</ref> and birds.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite journal
- Template:Cite magazine</ref><ref>Gouldian finch
Erythrura gouldiae Gynandromorph Template:Webarchive</ref><ref>Powdermill Banding Fall 2004 Template:Webarchive</ref><ref>A Gender-bender Colored Cardinal, by Tim Wall, Discovery News, 31 May 2011 [1] Template:Webarchive</ref><ref>Template:Cite news</ref> Although it can be seen in a variety of species, gynandromorphism is notably uncommon.<ref>Template:Cite journal</ref> Reporting depends on ease of detecting the phenomenon (whether a species displays noticeable sexual dimorphism) and how well-studied a region or organism is. For example, up until 2023 gynandromorphism had been reported in more than 40 bird species, but the vast majority of these are from the Palearctic and Nearctic; meanwhile, incidents in species from other regions may go underreported due to lack of data collection.<ref name=Stepniewski2023>Template:Cite journal</ref>
Pattern of distribution of male and female tissues in a single organismEdit
Several patterns of tissue distribution occur amongst observed gynandromorphs. Patch-like patterns may arise, but commonly the phenotype presents in a symmetrical pattern, of which there are three main types: bilateral, oblique, and transverse.<ref name=":1" /> Bilateral describes an organism that is split laterally with one side possessing female characteristics and the other having male characteristics. Oblique refers to a diagonal line across the sagittal plane that separates the male and female phenotypes. Lastly, transverse is a separation of male and female phenotypes along an axis that intersects with what would be considered the primary axis for the body of a given organism.<ref name=":1" />
A notable example in birds is the zebra finch. These birds have lateralized brain structures in the face of a common steroid signal, providing strong evidence for a non-hormonal primary sex mechanism regulating brain differentiation.<ref>Template:Cite journal</ref>
- Papilioandrogeusfemale.jpg
Normal female of Papilio androgeus
- Papilioandrogeusgynandromorph.jpg
Mosaic gynandromorph of Papilio androgeus
- Papilioandrogeosmale.jpg
Normal male of Papilio androgeus
CausesEdit
The exact cause for gynandromorphism is unknown, and appears to vary by species.<ref name=":0" /> One proposed cause for the phenotype in birds is a disruption that occurs in meiosis in female birds -- who possess ZW chromosomes -- in which polar bodies are not forced out of the cell.<ref name=":2">Template:Cite journal</ref> This is then followed with fertilization by two Z-bearing sperm cells which creates cells in the embryo containing both ZZ and ZW chromosomes.<ref name=":2" /> The same phenomenon can be seen in other species, such as Drosophila melanogaster, and creates a genetic mosaic which gives rise to the mixed phenotype.
As a research toolEdit
Gynandromorphs occasionally afford a powerful tool in genetic, developmental, and behavioral analyses. In Drosophila melanogaster, for instance, they provided evidence that male courtship behavior originates in the brain,<ref>Template:Cite journal</ref> that males can distinguish conspecific females from males by the scent or some other characteristic of the posterior, dorsal, integument of females,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> that the germ cells originate in the posterior-most region of the blastoderm,<ref>Template:Cite journal</ref> and that somatic components of the gonads originate in the mesodermal region of the fourth and fifth abdominal segment.<ref>Template:Cite journal</ref>
See alsoEdit
ReferencesEdit
External linksEdit
- "Stunning Dual-Sex Animals" at Live Science
- Aayushi Pratap: This rare bird is male on one side and female on the other; on: Sciencenews; October 6, 2020; about a gynandromorph rose-breasted grosbeak.